<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script type="text/javascript">
			
			//10毫秒-20毫秒
			function fn() {
				var d1 = new Date();

				for (var i = 0; i < 1000; i++) {
					var div=document.createElement("div");
					div.style.width="100px";
					div.style.height="2px";
					div.style.border="1px solid blue";
					document.body.appendChild(div);
				}
				var d2 = new Date();

				console.log(d2 - d1);
			}
			fn()
		</script>
	</body>
</html>
